Niche modelling of the Chilean recluse spider Loxosceles laeta and araneophagic spitting spider Scytodes globula and risk for loxoscelism in Chile

In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider Loxosceles laeta (Nicolet) (Araneae: Sicariidae). It is predated by the spitting spider Scytodes globula (Nicolet) (Araneae: Scytodidae). The biology of each of these species is not well known and it is important to clarify their distributions. The aims of this study are to elucidate the variables involved in the niches of both species based on environmental and human footprint variables, and to construct geographic maps that will be useful in estimating potential distributions and in defining a map of estimated risk for loxoscelism in Chile. Loxosceles laeta was found to be associated with high temperatures and low rates of precipitation, whereas although S. globula was also associated with high temperatures, its distribution was associated with a higher level of precipitation. The main variable associated with the distribution of L. laeta was the human footprint (48.6%), which suggests that this is a highly invasive species. Similarly to other species, the distribution of L. laeta reaches its southern limit at the Los Lagos region in Chile, which coincides with high levels of precipitation and low temperatures. The potential distribution of L. laeta in Chile corresponds to the distribution of cases of loxoscelism.     

The radiation of Satyrini butterflies (Nymphalidae: Satyrinae): a challenge for phylogenetic methods

We have inferred the most comprehensive phylogenetic hypothesis to date of butterflies in the tribe Satyrini. In order to obtain a hypothesis of relationships, we used maximum parsimony and model‐based methods with 4435 bp of DNA sequences from mitochondrial and nuclear genes for 179 taxa (130 genera and eight out‐groups). We estimated dates of origin and diversification for major clades, and performed a biogeographic analysis using a dispersal–vicariance framework, in order to infer a scenario of the biogeographical history of the group. We found long‐branch taxa that affected the accuracy of all three methods. Moreover, different methods produced incongruent phylogenies. We found that Satyrini appeared around 42 Mya in either the Neotropical or the Eastern Palaearctic, Oriental, and/or Indo‐Australian regions, and underwent a quick radiation between 32 and 24 Mya, during which time most of its component subtribes originated. Several factors might have been important for the diversification of Satyrini: the ability to feed on grasses; early habitat shift into open, non‐forest habitats; and geographic bridges, which permitted dispersal over marine barriers, enabling the geographic expansions of ancestors to new environments that provided opportunities for geographic differentiation, and diversification.

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False fairy wasps in Early Cretaceous amber from Spain (Hymenoptera: Mymarommatoidea)

Abstract: The fauna of false fairy wasps (Proctotrupomorpha: Bipetiolarida: Mymarommatoidea) occurring in Early Cretaceous (Albian) amber from north and north‐eastern Spain (Moraza, San Just, and El Soplao outcrops) is described. In total, 12 specimens have been recovered and four species recognized, all new: Alavaromma orchamum gen. nov. and sp. nov. (Alavarommatidae fam. nov.), Archaeromma hispanicum sp. nov. (Mymarommatidae), Galloromma alavaensis sp. nov., and G. turolensis sp. nov. (Gallorommatidae). The study indicates the necessity of revision and maybe fusion of both superfamilies, Mymarommatoidea and Serphitoidea, as the boundaries between them are less and less defined. However, major classificatory rearrangements must await the completion of the cladistic studies presently underway.     

Modulation of the arcuate nucleus–medial preoptic nucleus lordosis regulating circuit: A role for GABAB receptors

Estradiol rapidly activates a microcircuit in the arcuate nucleus of the hypothalamus (ARH) that is needed for maximal female sexual receptivity. Membrane estrogen receptor-α complexes with and signals through the metabotropic glutamate receptor-1a stimulating NPY release within the ARH activating proopiomelanocortin (POMC) neurons. These POMC neurons project to the medial preoptic nucleus (MPN) and release β-endorphin. Estradiol treatment induces activation/internalization of MPN μ-opioid receptors (MOR) to inhibit lordosis. Estradiol membrane action modulates ARH gamma-aminobutyric acid receptor-B (GABA_B) activity. We tested the hypothesis that ARH GABA_B receptors mediate estradiol-induced MOR activation and facilitation of sexual receptivity. Double-label immunohistochemistry revealed expression of GABA_B receptors in NPY, ERα and POMC expressing ARH neurons. Approximately 70% of POMC neurons expressed GABA_B receptors. Because estradiol initially activates an inhibitory circuit and maintains activation of this circuit, the effects of blocking GABA_B receptors were evaluated before estradiol benzoate (EB) treatment and after at the time of lordosis testing. Bilateral infusions of the GABA_B receptor antagonist, CGP52432, into the ARH prior to EB treatment of ovariectomized rats prevented estradiol-induced activation/internalization of MPN MOR, and the rats remained unreceptive. However, in EB-treated rats, bilateral CGP52432 infusions 30 min before behavior testing attenuated MOR internalization and facilitated lordosis. These results indicated that GABA_B receptors were located within the lordosis-regulating ARH microcircuit and are necessary for activation and maintenance of the estradiol inhibition of lordosis behavior. Although GABA_B receptors positively influence estradiol signaling, they negatively regulate lordosis behavior since GABA_B activity maintains the estradiol-induced inhibition.     

Calcium‐ and potassium‐permeable plasma membrane transporters are activated by copper in Arabidopsis root tips: linking copper transport with cytosolic hydroxyl radical production

Transition metals such as copper can interact with ascorbate or hydrogen peroxide to form highly reactive hydroxyl radicals (OH^?), with numerous implications to membrane transport activity and cell metabolism. So far, such interaction was described for extracellular (apoplastic) space but not cytosol. Here, a range of advanced electrophysiological and imaging techniques were applied to Arabidopsis thaliana plants differing in their copper‐transport activity: Col‐0, high‐affinity copper transporter COPT1‐overexpressing (C1^OE) seedlings, and T‐DNA COPT1 insertion mutant (copt1). Low Cu concentrations (10 µm ) stimulated a dose‐dependent Gd³⁺ and verapamil sensitive net Ca²⁺ influx in the root apex but not in mature zone. C1^OE also showed a fivefold higher Cu‐induced K⁺ efflux at the root tip level compared with Col‐0, and a reduction in basal peroxide accumulation at the root tip after copper exposure. Copper caused membrane disruptions of the root apex in C1^OE seedlings but not in copt1 plants; this damage was prevented by pretreatment with Gd³⁺. Our results suggest that copper transport into cytosol in root apex results in hydroxyl radical generation at the cytosolic side, with a consequent regulation of plasma membrane OH^?‐sensitive Ca²⁺ and K⁺ transport systems.     

Influence of Surface Chemistry on the Hygienic Status of Industrial Stainless Steel

Coupons of fourteen different stainless steels were investigated in terms of surface chemistry and ease of cleaning. Steel surfaces were exposed to Bacillus cereus spores in static saline solution for 2?h. Surfaces were rinsed and then covered with whole milk and allowed to dry. Surfaces were then cleaned in an experimental flow system that mimics an industrial application. After cleaning, remaining spores were released by sonication, spores cultured and colony forming units determined. Surfaces with higher levels of Fe in the outer surface of the passive film cleaned more easily. There was a relation between the polar component and ease of cleaning. The higher the polar component the more easily the surface cleaned. The cleaning mechanism involves dissolution of Fe enriched hydroxide films on the surface.     

An improved method using densitometry for evaluating severity of laser photocoagulation induced CNV

Laser photocoagulation induced choroidal neovascularization currently is the most effective model available for the study of this disease in terms of efficacy of new drugs and therapies. Previously, evaluating the extent of choroidal neovascularization using this model was time- consuming and required the use of experienced personnel. We describe a new method for simple and rapid evaluation of laser induced choroidal neovascularization using densitometry. Fluorescein angiograms of a laser photocoagulated rat eye were scanned into a computer. Densitometry software subsequently was used to calculate the severity of the laser lesions. The densitometry method proved effective for calculating the extent of laser induced choroidal neovascularization. In addition, this method was more rapid than visual evaluations and less likely to produce errors.     

Release of orphanin FQ/nociceptin in the medial preoptic nucleus and ventromedial nucleus of the hypothalamus facilitates lordosis

Opioid regulation of reproduction has been widely studied. However, the role of opioid receptor-like 1 receptor (NOP; also referred to as ORL-1 and OP4) and its endogenous ligand orphanin FQ/nociceptin (OFQ/N) have received less attention despite their extensive distribution throughout nuclei of the limbic-hypothalamic system, a circuit that regulates reproductive behavior in the female rat. Significantly, the expression of both receptor and ligand is regulated in a number of these nuclei by estradiol and progesterone. Activation of NOP in the ventromedial nucleus of the hypothalamus (VMH) of estradiol-primed nonreceptive female rats facilitates lordosis. NOPs are also expressed in the medial preoptic nucleus (MPN), however, their roles in reproductive behavior have not been studied. The present experiments examined the role of NOP in the regulation of lordosis in the MPN and tested whether endogenous OFQ/N in the MPN and VMH mediates reproductive behavior. Activation of NOP by microinfusion of OFQ/N in the MPN facilitated lordosis in estradiol-primed sexually nonreceptive female rats. Passive immunoneutralization of OFQ/N in either the MPN or the VMH reduced lordosis in estradiol-primed females, but had no effect on lordosis in estradiol+progesterone-primed sexually receptive rats. These studies suggest that OFQ/N has a central role in estradiol-only induced sexual receptivity, and that progesterone appears to involve additional circuits that mediate estradiol+progesterone sexual receptivity.     

Sexually dimorphic,androgen sensitive,enkephalinergic afferents to a lumbar motor nucleus of rats

In male rats, methionine-enkephalin immunoreactivity (enkephalin-ir) has been observed in the dorsal lateral nucleus (DLN), a longitudinal pool of motoneurons in the lumbar spinal cord. Within the DLN a mediodorsal crescent of intense enkephalin-ir staining surrounds the motoneurons innervating the ischiocavernosus muscle of the penis, which suggests a function of the enkephalinergic afferents in male copulatory activities. The present study attempted to determine the roles of gender and adult exposure to androgen in shaping the striking subnuclear distribution of enkephalin-ir. Transverse sections through L5–6 were obtained from mature male and female rats that were gonadally intact, gonadectomized, or gonadectomized and treated with testosterone, as well as from male rats genetically deficient in androgen receptors (Tfm). The sections were incubated with primary antiserum raised against methionine enkephalin and bound antibodies were visualized using the avidin-biotin peroxidase technique. A microphotometer was used to compare the staining density in laminae I-II of the dorsal horn, ventral grey matter, and the DLN. In all groups the DLN stained more darkly than the ventral grey, demonstrating the presence of enkephalin-ir in the DLN regardless of gender or exposure to androgen. However, the mediodorsal crescent of dense staining in the DLN was obvious only in gonadally intact males, while the entire DLN stained darkly in both sexes of gonadectomized rats treated with androgen. Therefore, the preferential distribution of enkephalin-ir in the mediodorsal crescent of the DLN is sexually dimorphic though the overall content of enkephalin-ir within the DLN responds to androgen.